Abstract
ABSTRACTThe performance of 200 F1Friesian ♂ × zebu ♀ and 90 zebu heifers on 14 dairy cooperative farms near Addis Ababa was compared over a 2-year period. The farms varied in management and feeding but in general the standards were low. Each farm had zebu and Friesian × zebu cows given the same management and feeding. Measurements were made of milk production traits of economic importance, including physiological and behavioural factors important for management purposes.The Friesian ♂ × zebu ♀ crossbred heifers showed an advantage in having an earlier age at puberty and at first calving, higher milk production, longer lactations, better disposition at milking and better reproductive performance. The calves from these crossbred heifers were larger at birth but there were more problems at calving. The zebu heifers withstood better the two periods of drought that occurred during the study. No significant differences were found in disease incidence, parasitic resistance, mastitis incidence or mortality. The interval between oestrus was normal in the F1heifers but longer in the zebus. The duration of gestation was much longer in the zebus (mean 291 days). The duration of oestrus was 4·5 h for the zebu and 10·0 h for the F1heifers, the latter being-much longer than the mean of 7·4 h reported in the literature. The F1heifers showed the first oestrus after calving much sooner than did the zebus.
Publisher
Cambridge University Press (CUP)
Subject
Animal Science and Zoology
Cited by
24 articles.
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